Joint for elbows and knees of artificial limbs



Oct. 1 1, 1927.

c, G. HOARE JOIKT FOR BLBOWS -AND KNEES OF ARTIFICIAL LIMES- Filed Feb.16. 1927 marsh/roe. 6ye/p, 6.//0meE;,

Patented Oct. 11, 1927.

UNITED STATES GYRIL GEORGE HOARE, OF I-I'OU'N SLOW, ENGLAND.

JOINT FOR ELBOWS AND KNEES OF ARTIFIGTALLIMBS.

Application filed February 16, 1927, Serial No. 188,773; and in GreatBritain November 3, 1925.

This invention relates to an improved joint for elbows and knees ofartificial arms and legs, and is of the type in which the lower memberof the arm or leg is movable 1 by hand or by means operable by theshoulder or hip into various adjusted positions from the fully flexedposition to the fully extended position with the arm or leg straight,and is locked. in any one of such positions or released therefrom.

In such limbs it is the practice to fit a metal mounting ring fixedlyinside the bucket of the upper arm or thigh to carry in suitablebearings the rotatable shafton which the firearm or lower member,secured thereto, can swing. A good example ofthis practice is shown inthe specification and drawings of the prior U. S. Patent No. 1,507,998granted to the present applicant and anoth-er.- Sometimes,in modelsdesigned for light work, the shell of the lower memher fits over thebucket and is attached to the outer ends of the said rotatable shaftwhich project through or are accessible on the exterior of the bucket(as inthe said prior case). But the-present invention concerns moreparticularly models known as heavy-working t-ype wherein the lowermember is detachably secured to a T-piece construction, i. e. to a rodformed. with or fixed to the rotatable shaft at or about its middle, andright-angularly ext-ending therefrom through a slot in the bucket. v

With the heavy-working type of limb, wherein the lower member may beadapted or employed for comparatively heavy work entail-ing strain onthe various fittings, a difiiculty is experienced in securing the metalmounting. ring in a sufficiently strong. manner to avoid damage underthestrai'n. The

' screws attaching the ring may shear or tear through the bucket. Otherdefects are inher-ent with such a construction when applied to theheavy-working'typ'e.

The primary object of the present invention is to improve the method ofmounting the rotatable shaft in the bucket, dispensing with a mountingring as described above. Another object is to provide improved lockingmeans'of the type wherein a plunger co-acts with holes on a sector fixedon the rotatable shaft, the plunger being reciprocat-ed b a cam devicesuitably actuated.

Broa 1y, according tothe invention, the

' bucket of the upper limb member is constructed not of pressed or spinsheet metal as usually obtains, but as a sturdy solid the followingdescription, in detail, of an embodiment, illustrated by theaccompanying drawings, wher'e'1n:

I Figure 1 is a vertical section of the joint,

the lower limb member'beingdetached and omitted. The section is on theline-II of Figure 3.

Figure 2 is a View of the new cast metal bucket with the variousfittings removed.

Figure 3 is a transverse section on the line II'IIIT of Figure l, thebucket (F igure 2) being omitted, and the arm for attachment of thelower limb being shown swung. intoia flexed position at right-angles tothe Figure '1 position.

Referring to the' drawings, the bucket formed with the upper limb member1 is constructed as a stout metal casting of aluminium or a suitablelight alloy), but is not-completely cylindrical in its body. It isdivided longitudinally so that, in form, it is semi-cylindrical at 2,terminating in a semi cup-shaped end 3. Interiorly, there is formedintegrally a pair of parallel. semicircularfiribs 4. extending from onelongitudinal edge of the bucket to the other, and constituting betweenthem a semi-circular recess or slideway. recess may be machined orotherwise formed into any suitable cross-section, a rectangular sectionbeing suitable, as illustrated.

The rotatable shaft 5' and its various fittings are mounted on asemi-circular metal mounting frame 6 (serving the purpose of themounting ring in the previous mentioned example), and saidframe isadapted to drop into therecess or slidewa'y between the ribs 4, 4. Now,as all heavy strains are mainly along the longitudinal axis of thebucket, or nearer this axis than at right-angles thereto, it will'beseen that strains seeking to dislodge the mounting frame 6 are'solidluntil the lower member approaches a 90- degree flexing as in the Figure8 position.

In constructing such a bucket, it is preferred to make the top 8undivided longitudinally, so that a complete annular portion ispresented for a requisite depth where the upper limb member 1 is joinedthereto, and to provide a mounting flange 9 for an exterior light sheetmetal or equivalent bucket/10 which is fitted over the assembly abovedescribed, and formed with a slot 11 through which the T-piece 12 of therotatable shaft 5 can project and in which it can swing.

regarding the locking means, it is found convenient to adopt thefollowing construction with the aforesaid slidably removablesemi-circular mounting frame 6. The rot-atable shaft- 5 is mounteddiametrically between the two horns of the mounting frame in suitablebearings 13. The T-piece arm 12 is carried by a boss 14. fittingcentrally on the shaft 5 and clamped, screwed or otherwise held fixedlythereon. The said boss is formed with a sector member 15 which swings ina plane at right-angles to the shafts axis as the shaft turns.

In the base of the semi-circular frame 6 a plunger socket 16 is formed(preferably in the one casting) having its longitudinal axis parallel tothat of the shaft 5; the plunger 17 mounted therein is adapted to buttagainst the aforesaid sector member 15, and enter one of a series ofholes 18 in the said sector. The plunger 17 is operable by a sin devicemount-ed on the rotatable shaft 5, thecain being a sleeve 19 revolubleon the shaft, and having a helical or inclined slot- 20 cut in itsperiphery. A right-angularly projecting pin 21 from the plunger 17extends through a slot in the plunger socket 16 and enters said camslot20,.thus partial rotation of the cam 19 will impart a reciprocation tothe plungc1117. A spring 22 is provided to keep the cam in the normallylocking position, and means are provided to m'ovethe cam when desired. 7

The means to movethe cam may be the chain 23'secured between the camsleeve 19 and lever 2%, the latter being operated by A catch 26 on theouter cup 10 )7 strap 25. can be used to hold the lever/24 inthe upposition-plunger 1'? retracted, and segment 15 free. A. strap 2? may besecured to the arm 12, passing over the to") of the mechanism and outthrough the slot 28 for the purpose of flexing the lower limb member.

The lower limb member not shown) is at tached to the arm 12, and thelatter is. a common fitting forming no part of the present invention.

metal bucket having an upper portion oi.

I elaim:-

1. In joints for elbows and knees of artiticial limbs, a cast metalbucket for the up per limb member having a slideway at right angles tothe-vertical axis of the bucket, a mounting frame'fitted in saidslideway, and a rotatable shaft carried by the mounting frame. i I i '2.In joints for artificial limbs. a cast 79 metal bucket adapted to beattached to the upper limb, said bucket having a substantiallysemi-cylindrical body tern'iinating in a semi-cup-shaped end, a pair ofintegral pan; allel ribs formed in a horizontal plane on the interior ofthe bucket, a mountin frame fitted between said ribs, and a rotatableshaft carried by said mounting frame.

3. A joint for artificial limbs con'iprising a cast metal bucket havingspaced parallel ribs on the inside face thereof, a mounting frame seatedbetween said ribs, said mounting frame being of substantially Ushapedformation, a shaft journaled in the opposite 7 arm portions of saidframe, an arm keyed to said shaft, a perforated segment carried by thearm, a locking pin slidably positioned in the mounting frame andadapted'to be projected into one of the perforations of said segment,means for operating said arm and means for operating said locking pin. r

4;. In ioints for artificial limbs,

substantially cylindrical formation and adapted to fit into the upperlimb member and having its lower portion of substantl; lysemi-cylindrical formation and rounded at its lower portion toward thevertical axis of the bucket, and spaced parallel ribs formed on theinside of the bucket'on the said semicylindrical portion thereof. 7

5. A. jointfor elbows and knees of" artificial limbs comprising a bucketmember adapted to fit into the upper limb, an arm mounting frame for thelower limb secured to the inside of the bucket member, said frameincluding opposite journal portions, a shaft bearing in saidjournalportions, a

lower limb mounting member keyed to said shaft, and means forlockingsaid arm comprising a portion of the arm member havii g aseriesof arcuately arranged openings,

'slidable latch member projectable into said openings, and means foroperating said latch member including cam mounted on the shaftand'operatively interlocked with said latch member, and means foroperating said cam.

. Intestimony fixed my signature this 1st day of crane enonen noans;

whereof I have hereunto af- February,

